CVE-2008-1891

Directory traversal vulnerability in WEBrick in Ruby 1.8.4 and earlier, 1.8.5 before 1.8.5-p231, 1.8.6 before 1.8.6-p230, 1.8.7 before 1.8.7-p22, and 1.9.0 before 1.9.0-2, when using NTFS or FAT filesystems, allows remote attackers to read arbitrary CGI files via a trailing (1) + (plus), (2) %2b (encoded plus), (3) . (dot), (4) %2e (encoded dot), or (5) %20 (encoded space) character in the URI, possibly related to the WEBrick::HTTPServlet::FileHandler and WEBrick::HTTPServer.new functionality and the :DocumentRoot option.

Published: 2008-04-18 Last update: 2026-06-16 Assigner: [email protected] Source: [email protected]
NVD Status：Modified，CVE State: published
View at NVD, CVE.org, EUVD

CVE-2008-1891 is rated Moderate Risk (51.9/100): CVSS Medium severity, with medium exploitation likelihood (EPSS 2.81%). EPSS rose +2.28% over the last day, indicating growing attacker interest. Review affected assets and schedule remediation.

Risk is dynamic; we continuously reassess and refresh what is shown on this page as upstream context changes.

Exploit prediction scoring system (EPSS) score for CVE-2008-1891

EPSS lead: Daily EPSS estimates relative likelihood of exploitation; percentile ranks this CVE among scored vulnerabilities (higher = more severe relative rank).

# Date Old EPSS score New EPSS score Delta (New - Old)
1 2026-06-15 0.53% 2.81% +2.28%
2 2026-06-03 0.21% 0.53% +0.33%
3 2026-06-01 — 0.21% —

Full EPSS history (19 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2008-1891

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
5.0 2.0 MEDIUM
AV:N/AC:L/Au:N/C:P/I:N/A:N Click to expand
Access vector (AV:N)
Can be exploited remotely over network reachability.
Access complexity (AC:L)
Exploitation conditions are straightforward and predictable.
Authentication (AU:N)
No authentication is required.
Confidentiality impact (C:P)
Partial confidentiality impact.
Integrity impact (I:N)
No integrity impact.
Availability impact (A:N)
No availability impact.
 10.0 2.9 [email protected]

Weakness enumeration for CVE-2008-1891

OS Trackers for CVE-2008-1891

vendor priority summary link
redhat low — https://access.redhat.com/security/cve/CVE-2008-1891
ubuntu negligible CVE-2008-1891 negligible priority: Ubuntu including 2 source packages (ruby1.8, ruby1.9), 10 status rows across 5 suites (dapper, feisty, gutsy, hardy, upstream): ignored 8, released 2. https://ubuntu.com/security/CVE-2008-1891

Vendor comments (NVD) for CVE-2008-1891

  • Red Hat (2009-06-10T00:00:00)

    Red Hat is aware of this issue and is tracking it via the following bug: https://bugzilla.redhat.com/bugzilla/show_bug.cgi?id=CVE-2008-1891 The risks associated with fixing this flaw outweigh the benefits of the fix. Red Hat does not plan to fix this flaw in Red Hat Enterprise Linux.

Affected software / configurations for CVE-2008-1891

Vendor Product Version Raw CPE
ruby-lang ruby <= 1.9.0 cpe:2.3:a:ruby-lang:ruby:*:*:*:*:*:*:*:*
ruby-lang ruby 1.8.5 cpe:2.3:a:ruby-lang:ruby:1.8.5:*:*:*:*:*:*:*
ruby-lang ruby 1.8.6 cpe:2.3:a:ruby-lang:ruby:1.8.6:*:*:*:*:*:*:*

References for CVE-2008-1891

cvelogic Threat Intelligence